<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <img src="./images/wb.jpg" alt="" />
    <script>
      //1.获取广告元素
      var img = document.querySelector('img');
      // 2设置定时器
      setTimeout(function () {
        img.style.display = 'none';
      }, 3000);
    </script>
  </body>
</html>
